Regular Users of Marijuana Can Require More Sedatives During Medical Procedures

Marijuana’s interaction with other drugs is still poorly understood. (Credit: Shutterstock)

Increasing numbers of Americans are using marijuana. In some states, obtaining marijuana is as easy as walking into a store and picking out what catches the eye in a glass display case. But even as states move to legalize recreational and medical cannabis, it remains a taboo topic, even in doctors’ offices.

Now, a new study suggests that keeping marijuana use secret from medical professionals probably isn’t a good idea. A team of researchers in Colorado has found that people who regularly use marijuana require more of a few commonly-used sedatives and anesthesia before routine medical procedures.

The study, published in The Journal of the American Osteopathic Association, analyzed the medical records of 250 people who underwent endoscopies, which are procedures that involve a doctor inserting a camera inside of a person’s body to see what’s happening inside. Of the 25 people who reported smoking marijuana or using edible cannabis products on a daily or weekly basis, the researchers say they needed higher doses of drugs and anesthesia to achieve optimal sedation.

On average, cannabis users needed 14 percent more fentanyl, 20 percent more midazolam, and 220 percent more propofol before colonoscopies and other routine medical procedures. The researchers say this finding is significant because higher doses often means a higher likelihood of negative — and potentially dangerous — side effects.

“Some of the sedative medications have dose-dependent side effects, meaning the higher the dose, the greater likelihood for problems. That becomes particularly dangerous when suppressed respiratory function is a known side effect,” said lead researcher Mark Twardowski, an osteopathic internal medicine physician in Grand Junction, Colo., in a statement.

In colonoscopies, which made up the majority of cases the researchers reviewed, midazolam and propofol are the most commonly used sedatives, and fentanyl is a frequently used as a painkiller. Because the researchers only studied marijuana’s impact on these three drugs, it’s unknown if marijuana would interact with other sedatives on the market.

Nature’s Medicine?

It’s not totally clear how marijuana interacts with the three drugs studied. The researchers think it might have something to do with how the main psychoactive chemical compound in marijuana, called tetrahydrocannabiol (THC), interacts with the body’s endocannabinoid and opioid systems. These are two interrelated neurotransmitter systems that are involved in drug processing, pain, and more. THC may bind to these receptors and alter how other drugs are metabolized. People who frequently use cannabis may need higher doses of certain sedatives to be effective, as this study found.

But more research is needed to understand how marijuana, which has at least 85 cannabinoids and 27 terpenes, impacts processes in the human body and how its chemical compounds interacts with other drugs. Marijuana is still illegal at the federal level in the United States, which also has policies and regulations in place that limit research.

While research lags, consumption of the drug is booming. The study noted that between 2007 and 2015, marijuana use in the United States increased 43 percent. An estimated 13.5 percent of the adult of adults used marijuana over this period, with the greatest increases among people 26 and older.

But even as marijuana becomes more mainstream, people who use cannabis may want to be mindful that it’s still new to the medical community.

“Cannabis has some metabolic effects we don’t understand and patients need to know that their cannabis use might make other medications less effective. We’re seeing some problematic trends anecdotally, and there is virtually no formal data to provide a sense of scale or suggest any evidence-based protocols,” Twardowski said.